Administration Console Online Help

JMS Topic: Configuration: Thresholds and Quotas

Use this page to define upper and lower byte and/or message thresholds
for the topic. Exceeding these thresholds will trigger events such as
generating log messages and starting message flow control. You can also
specify a maximum size allowed for messages on the topic and select a
pre-configured quota, which determines the maximum number of bytes or
messages that the topic is allowed to store to conserve memory use.

If a JMS template is specified for this topic, then the default values
imply that the actual value will come from the template. A JMS server can
also manage thresholds and certain quota settings for all destinations in
a JMS module targeted to that JMS server.

The upper threshold (total number of bytes in this destination)
that triggers logging or flow control events. The value of
java.lang.Long.MAX_VALUE disables logging and flow control events
for the destination.

If the number of bytes exceeds this threshold, the triggered
events are:

Log Messages

A message is logged on the server indicating a high threshold
condition.

Flow Control

If flow control is enabled, the destination becomes armed and
instructs producers to begin decreasing their message flow.

Range of Values: <= BytesMaximum;
>BytesThresholdLow

Any change to this threshold affects only incoming messages;
stored messages are not affected.

The lower threshold (total number of bytes in this destination)
that triggers logging or flow control events. The value of
java.lang.Long.MAX_VALUE disables logging and flow control events
for the destination.

If the number of bytes falls below this threshold, the triggered
events are:

Log Messages

A message is logged on the server indicating a low threshold
condition.

Flow Control

If flow control is enabled, the destination becomes disarmed and
instructs producers to begin increasing their message flow.

Range of Values: < BytesThresholdHigh

Any change to this threshold affects only incoming messages;
stored messages are not affected.

The upper threshold (total number of messages in this
destination) that triggers logging or flow control events. The
value of java.lang.Long.MAX_VALUE disables logging and flow control
events for the destination.

If the number of messages exceeds this threshold, the triggered
events are:

Log Messages

A message is logged on the server indicating a high threshold
condition.

Flow Control

If flow control is enabled, the destination becomes armed and
instructs producers to begin decreasing their message flow.

Range of Values: <= MessagesMaximum;
>MessagesThresholdLow

Any change to this threshold affects only incoming messages;
stored messages are not affected.

The lower threshold (total number of messages in this
destination) that triggers logging or flow control events. The
value of java.lang.Long.MAX_VALUE disables logging and flow control
events for the destination.

If the number of messages falls below this threshold, the
triggered events are:

Log Messages

A message is logged on the server indicating a low threshold
condition.

Flow Control

If flow control is enabled, the destination becomes disarmed and
instructs producers to begin increasing their message flow.

Range of Values: < MessagesThresholdHigh

Any change to this threshold affects only incoming messages;
stored messages are not affected.

The maximum size of a message that is accepted from producers on
this destination.

The message size includes the message body, any user-defined
properties, and the user-defined JMS header fields:
JMSCorrelationID and JMSType . Producers sending
messages that exceed the configured maximum message size for the
destination receive a ResourceAllocationException .

The maximum message size is only enforced for the initial
production of a message. Messages that are redirected to an error
destination or forwarded to a member of a distributed destination
are not checked for size. For instance, if a destination and its
corresponding error destination are configured with a maximum
message size of 128K bytes and 64K bytes, respectively, a message
of 96K bytes could be redirected to the error destination (even
though it exceeds the 64K byte maximum), but a producer could not
directly send the 96K byte message to the error destination.

This attribute is dynamically configurable, but only incoming
messages are impacted; stored messages are not impacted.